View source for 1ybh


==Crystal structure of Arabidopsis thaliana Acetohydroxyacid synthase In Complex With A Sulfonylurea Herbicide Chlorimuron Ethyl==
<StructureSection load='1ybh' size='340' side='right'caption='[[1ybh]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ybh]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YBH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1YBH FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CIE:2-[[[[(4-CHLORO-6-METHOXY-2-PYRIMIDINYL)AMINO]CARBONYL]AMINO]SULFONYL]BENZOIC+ACID+ETHYL+ESTER'>CIE</scene>, <scene name='pdbligand=CSD:3-SULFINOALANINE'>CSD</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NHE:2-[N-CYCLOHEXYLAMINO]ETHANE+SULFONIC+ACID'>NHE</scene>, <scene name='pdbligand=P22:ETHYL+DIHYDROGEN+DIPHOSPHATE'>P22</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1ybh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ybh OCA], [https://pdbe.org/1ybh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ybh RCSB], [https://www.ebi.ac.uk/pdbsum/1ybh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ybh ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ILVB_ARATH ILVB_ARATH] Catalyzes the formation of acetolactate from pyruvate, the first step in valine and isoleucine biosynthesis.<ref>PMID:16665813</ref> <ref>PMID:2336405</ref> [:]<ref>PMID:16667374</ref> <ref>PMID:16668488</ref> <ref>PMID:8913312</ref> <ref>PMID:9355748</ref> <ref>PMID:9677339</ref> <ref>PMID:10386618</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/yb/1ybh_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1ybh ConSurf].
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== Publication Abstract from PubMed ==
The sulfonylureas and imidazolinones are potent commercial herbicide families. They are among the most popular choices for farmers worldwide, because they are nontoxic to animals and highly selective. These herbicides inhibit branched-chain amino acid biosynthesis in plants by targeting acetohydroxyacid synthase (AHAS, EC 2.2.1.6). This report describes the 3D structure of Arabidopsis thaliana AHAS in complex with five sulfonylureas (to 2.5 A resolution) and with the imidazolinone, imazaquin (IQ; 2.8 A). Neither class of molecule has a structure that mimics the substrates for the enzyme, but both inhibit by blocking a channel through which access to the active site is gained. The sulfonylureas approach within 5 A of the catalytic center, which is the C2 atom of the cofactor thiamin diphosphate, whereas IQ is at least 7 A from this atom. Ten of the amino acid residues that bind the sulfonylureas also bind IQ. Six additional residues interact only with the sulfonylureas, whereas there are two residues that bind IQ but not the sulfonylureas. Thus, the two classes of inhibitor occupy partially overlapping sites but adopt different modes of binding. The increasing emergence of resistant weeds due to the appearance of mutations that interfere with the inhibition of AHAS is now a worldwide problem. The structures described here provide a rational molecular basis for understanding these mutations, thus allowing more sophisticated AHAS inhibitors to be developed. There is no previously described structure for any plant protein in complex with a commercial herbicide.

Herbicide-binding sites revealed in the structure of plant acetohydroxyacid synthase.,McCourt JA, Pang SS, King-Scott J, Guddat LW, Duggleby RG Proc Natl Acad Sci U S A. 2006 Jan 17;103(3):569-73. Epub 2006 Jan 10. PMID:16407096<ref>PMID:16407096</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Duggleby RG]]
[[Category: Guddat LW]]
[[Category: King-Scott J]]
[[Category: McCourt JA]]
[[Category: Pang SS]]